The information age has produced an explosion of content for people to read. Searchable content is often electronically stored in information databases which may be accessed locally or which may be accessed remotely via a private network, such as an intranetwork, or a public network, such as the Internet. Various search engines are available for searching such content in response to a query from a user. The search results returned by the search engine often include text, images, links to other Web pages or Web sites, etc. Images may include graphics, such as charts, drawings, diagrams, pictures, photos, etc. Accordingly, images often have richer information content than written text, and thus, are more efficient vehicles for conveying information than plain text. For example, to describe the information contained in a single picture or drawing, many pages of text may have to be written. Moreover, people may be quicker to spot desired information in an image or group of images than in several pages of text. One reason for the quick visual recognition of desired information is that the human visual cortex processes visual information in parallel, whereas reading is inherently a sequential process. Hence, visual information often provides higher efficiency over written text.
Given the above, providing images in response to search queries, in addition to or in lieu of text, often enhances the user experience, and improves efficiency and effectiveness of the search. Images that may be displayed in response to search queries may be found on Web pages made available via the Internet. Another repository for images is private image archives. Such images are often stored in individual image files that are indexed and maintained in an information database and/or Web server. Less utilized in response to search queries are images from within sources such as books, magazines, newspapers, newsletters, manuals, guides, references, articles, reports, documents, etc. Currently, no methods or systems are available which provide images from within such sources in response to a search query. For example, a web search for a keyword “ship” may return information about ship manufacturers, ship building, cruise ships, etc., but the search results, most probably, will not include an image of a ship from within a book, such as a book on the Titanic or other historical or technical books related to ships, unless such an image is saved in an indexed information database as an individual image file. Accordingly, images from within sources such as books constitute a rich source of untapped information for search engines.